The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 08, 1992
Filed:
Oct. 25, 1991
Applicant:
Inventor:
Viesturs Lesins, Buffalo, NY (US);
Assignee:
Occidental Chemical Corporation, Niagara Falls, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ; C07D / ;
U.S. Cl.
CPC ...
549250 ; 549236 ; 549239 ; 549241 ; 549247 ;
Abstract
A process for the preparation of purified oxydiphthalic acid from impure oxydiphthalic anhydride, by treating with a mixture of water and propionic acid or butyric acid to produce oxydiphthalic acid. The acid may be treated to reform oxydiphthalic anhydride. The most effective composition range for the acid-water mixture is from about 25% acid to 75% acid.